DESCRIPTION: (applicant's abstract) Genetics of biological nitrogen fixation is a highly complex system which consists of a number of nitrogen fixing (nif) genes and their protein products, with twenty identified to-date. The specific functions of most of these genes are not known. The goal of this research proposal is to identify possible interactions of the Fe-protein with other proteins of the nif-cluster. The Principal Investigator proposes to take a molecular genetic approach using the MATCHMAKER Yeast Two-Hybrid System to investigate the networking of nif-specific protein-protein interactions. Currently there is a lot of information in the literature that suggests possible roles for these accessory proteins. By using the experimental system described in the proposal, the Principal Investigator hopes to identify interactions among these accessory proteins. The results that will be obtained can be analyzed in light of previously proposed functions. These studies are expected to have an impact not only on functional genomics of the Fe-protein but also on our understanding of a variety of fundamental issues in biology. Furthermore, the experimental systems employed in the study will be an excellent tool to introduce senior undergraduate students to an active research laboratory; hence, this research concept will be incorporated into a molecular methods laboratory course planned at Bowling Green State University during this grant period.